A common use of wireless technologies involves tracking an asset (e.g., a pet, car, person, etc.) using a portable and wireless tracking device. In one approach to such uses, the wireless tracking device may communicate wirelessly with one or more beacons to determine when the wireless tracking device enters, remains inside, and/or leaves a predetermined area or areas (i.e., a beacon fence).
Frequency hopping spread spectrum (FHSS) transmission methods provide a robust and efficient way to provide the wireless communications between a wireless tracking device and a beacon in such applications. However, FHSS methods require synchronization between the beacon and the wireless tracking device in order to coordinate the sequence of pseudorandom frequency hops of the carrier signal. If the wireless tracking device and beacon lose synchronization, the wireless tracking device may consume significant amounts of power trying to reestablish synchronization with the beacon. For example, once out of sync with the beacon, the wireless tracking device would not know the next frequency hop and would have to expend power guessing frequencies to try to find the beacon again. A wireless tracking device could waste substantial amounts power by guessing incorrectly or guessing while the wireless tracking device is out of range. High power consumption in such situations may be undesirable since wireless tracking devices usually have a limited power supply (i.e., a battery). Additionally, a wireless tracking device using traditional FHSS methods may waste substantial amounts of time searching for the frequency hopping pattern transmitted by the beacon because in traditional FHSS methods all the pseudorandom frequencies must be searched by the wireless tracking device to reestablish synchronization with the beacon.